I have also been where you are.
I agree with Briefcase that you should focus on yourself. Here are some things I started doing that really helped me get through, and eventually started leading to progress in my relationship with my uBPD H:
1) Learning and using validation skills better
2) Having time to myself
3) Knowing in my heart that I wasn't do anything wrong
4) Knowing in my heart that if this r/s didn't improve I would survive (even though it would hurt)
5) Dealing with my sadness/anger on my own and not with H (self soothing)
Sounds like you definitely need some self soothing right now. I have done everything from cry in the bathroom, to meet with a friend who understood and could give me a hug and let me cry if I needed to. I've also found other things that help me release the feelings in a more positive way. Someone suggested I make of list of things that make me happy so I can get over the pain without bringing it into my relationship (b/c H wasn't capable of helping me deal with that)
My list includes: 1) Cuddling with my dog 2) Baking 3) Journaling 4) Painting or sketching
What would be on your list?
I also want to tell you, it can get better. I hope you have a good support system (in person) around you right now. Cyber hugs don't always cut it
B.